It has become clear the last few years that in the very near future our civilization will require great increases in the production of electrical power to meet the growing power demands of our increasingly mechanized and industrialized society. It is also clear, for a number of reasons, that it will be highly desirable if the increased electrical power is provided from sources other than a conventional steam turbine generator using coal or oil as its fuel.
One reason for this latter fact is that the available supply of fossil fuels such as coal and oil is limited. A second reason is the serious pollution problem that has already arisen from the burning of coal and oil to obtain electrical power. (In fact, many of the very methods which have been suggested for combating our present or prospective levels of pollution will themselves require electrical power, and thus will present an added pollution problem if they are put into effect relying on a source of power that requires the burning of still more coal and oil.) A third reason is that new sources of electrical power will hopefully produce a substantial reduction in the cost of producing such power. Finally, the desirability of conserving fossil fuels for their value to the chemical industry, particularly in the resin field, is very clear.
Nuclear power is now used to some extent as a substitute for coal or oil for the production of superheated steam for use in conventional steam turbine generators. But neither coal, oil, nor nuclear power achieves a very high level of efficiency in this mode of generating electrical power.
In accordance with the laws of thermodynamics and mechanical efficiency, the maximum theoretical efficiency for a steam turbine is about 45 percent. As a practical matter, coal and oil powered electrical generators usually operate at only about 39 percent efficiency. Nuclear electrical plants usually operate, under normal operating procedure, at a still lower level--only about 32 percent efficiency. Even with the remarkably improved theoretical efficiency projected for the magnetohydrodynamic generator coupled with a steam generator, it is believed that the maximum efficiency obtainable with such a system would be no more than about 55 to 65 percent for an extremely large and efficient plant.